Field
The following description relates generally to wireless communications, and more particularly to offline discontinuous reception (DRX) processing in a cellular system.
Background
Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, and orthogonal frequency division multiple access (OFDMA) systems.
Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals (e.g., access terminals, mobile stations, mobile devices, user equipment (UE)). Each terminal communicates with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. The communication links may be established via a single-in-single-out, multiple-in-signal-out or a multiple-in-multiple-out (MIMO) system.
In a communication system, the network consists of several base stations, each one of which covers its respective area (e.g., cell) and communicates with one or more mobile devices. When there is an incoming voice or data call, a paging message is sent from a set of base stations where the network determines that the mobile device is likely to be present.
In a conventional paging procedure, two signals are used to convey the paging message. The first paging signal transmitted via Physical Downlink Control Channel (PDCCH) is used to indicate whether a paging message is being transmitted to a particular mobile device or group of mobile devices. The second paging signal transmitted via Physical Downlink Shared Channel (PDSCH) carries the paging message(s) (e.g., page payload) for the particular mobile device or group of mobile devices. The first paging signal and the second paging signal may be transmitted in the same subframe (e.g., paging occasion).
Typically, mobile devices utilize power (e.g., battery power) while turned on as well as during periods of communication with a base station and/or other mobile devices via the base station. The amount of power consumed by a mobile device can depend in part on the configuration of the mobile device and/or function (e.g., operation) being performed by the mobile device. Reducing the amount of power utilized by a mobile device is desirable as such reduction can result in extended battery life and decreased cost to use the mobile device and battery in addition to improved overall performance of the mobile device.
Typical mobile devices use Discontinuous Reception (DRX) in idle mode to reduce power consumption. When DRX is used, the mobile device monitors the first paging signal only at one paging subframe (e.g., paging occasion) per DRX cycle. The core network usually knows when the mobile terminal will be monitoring the first paging signal within the DRX cycle. Thus, if the network intends to page a particular mobile terminal, it sends the first paging signal at the time when the mobile terminal will be monitoring the paging channel. If the mobile terminal is not paged in the first paging signal, it goes back to the idle mode. Otherwise, the mobile terminal reads the second paging signal.
Typically, a mobile device implementing DRX would be required to bring an transceiver online and maintain it online in order to effectively perform the decoding and processing necessary to determine whether the received page is intended for the receiving mobile device or some other device. During this time, however, the transceiver of the mobile device can consume a significant amount of battery power. Accordingly, there exists a need for a system configuration that allows the mobile device to capture time domain (TD) samples (e.g., paging subframe) and shut off the transceiver as quickly as possible while performing the necessary DRX processing in idle mode. This would allow for lower current consumption during DRX processing, resulting in significant idle mode current savings.